epithalamin raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-08-10 and is reviewed periodically as new material appears.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
O-GlcNAc has been found to slow protein aggregation, though the generality of this phenomenon is unknown. Solid-phase peptide synthesis was used to prepare full-length α-synuclein with an O-GlcNAc modification at T72. Thioflavin T aggregation assays and transmission electron microscopy demonstrated that this modified α-synuclein does not readily form aggregates. Treatment of JNPL3 tau transgenic mice with an OGA inhibitor was shown to increase microtubule-associated protein tau O-GlcNAcylation. Immunohistochemistry analysis of the brainstem revealed decreased formation of neurofibrillary tangles. Recombinant O-GlcNAcylated tau was shown to aggregate slower than unmodified tau in an in vitro thioflavin S aggregation assay. Similar results were obtained for a recombinantly prepared O-GlcNAcylated TAB1 construct versus its unmodified form.
Fully aquatic mammals, the cetaceans and sirenians, have lost their legs and have a tail fin to propel themselves through the water. Flipper movement is continuous. Whales swim by moving their tail fin and lower body up and down, propellling themselves through vertical movement, while their flippers are mainly used for steering. Their skeletal anatomy allows them to be fast swimmers. Most species have a dorsal fin to prevent themselves from turning upside-down in the water. The flukes of sirenians are raised up and down in long strokes to move the animal forward, and can be twisted to turn. The forelimbs are paddle-like flippers which aid in turning and slowing. Semi-aquatic mammals, like pinnipeds, have two pairs of flippers on the front and back, the fore-flippers and hind-flippers. The elbows and ankles are enclosed within the body. Pinnipeds have several adaptions for reducing drag. In addition to their streamlined bodies, they have smooth networks of muscle bundles in their skin that may increase laminar flow and make it easier for them to slip through water. They also lack arrector pili, so their fur can be streamlined as they swim. They rely on their fore-flippers for locomotion in a wing-like manner similar to penguins and sea turtles. Fore-flipper movement is not continuous, and the animal glides between each stroke. Compared to terrestrial carnivorans, the fore-limbs are reduced in length, which gives the locomotor muscles at the shoulder and elbow joints greater mechanical advantage; the hind-flippers serve as stabilizers.
=== Host immune response === Fibroblasts from different anatomical sites in the body express many genes that code for immune mediators and proteins. These mediators of immune response enable the cellular communication with hematopoietic immune cells. The immune activity of non-hematopoietic cells, such as fibroblasts, is referred to as "structural immunity". In order to facilitate a fast response to immunological challenges, fibroblasts encode crucial aspects of the structural cell immune response in the epigenome.
Stoess, on the other hand, had reestablished relations with Eastman Kodak in the United States and was bringing large quantities of much-needed foreign exchange to Germany. After World War II, Paul Koepff Jr. became managing director of the Stoess company in Eberbach. In 1949, he built up a gelatin capsule factory there. In the course of the decades, DGF AG bought various factories worldwide. In 1965, it was taken over by the "Chem. Werke Stoess" in Heidelberg. In that year Heinrich Koepff took over the majority of shares of the Göppingen plant and through his marriage to the granddaughter of the company founder, Gerda Stoess, the companies merged. In 1972, the association traded under the name DGF Stoess & Co. GmbH. In 1989, the company was converted into a public limited company. The gelatin production division was renamed the Gelita Group in 1999. In 2005, all entities started to sell gelatine under the brand name Gelita.
Sources: en.wikipedia.org
Currently approved CCEEVs are also more thermotolerant than the label suggests: a commercial CCEEV packaged as a ready-to-inject solution in a vial, with a 2–8 °C recommendation from the manufacturer, was found to have lost none of its effectiveness in dogs after spending three months at 30 °C (86 °F). It is believed that liquid vaccines degrade by processes such as aggregation of protein particles, so dry human vaccines are expected to be even more stable. Indeed, a human CCEEV was found to remain effective after three months at 37 °C (99 °F).
Zhang's tactics included propaganda, intelligence-gathering, and involvement in the opium trade, while Liu fought back with counter-propaganda and appointing loyalist magistrates who frustrated Zhang's work. Liu triumphed in 1942 when the 36th Division was moved to the Yunnanese front, and Zhang was transferred back to Chongqing in 1946. Zhang's presence was replaced by He Guoguang, but Liu continued frustrating Nationalist centralization attempts. In 1944 during Operation Ichi-Go, there was once again talk of moving the capital to Xichang, encouraged by American General Wedermeyer, but this was abandoned after the Japanese offensive stalled. In late 1942, Chiang ordered Liu and Ma Bufang of Qinghai to mobilize for a campaign against Tibet. Liu was suspicious of the Nationalist leader's motivations, dispatching his chief of staff Wu Peiying (伍培英) to Chongqing to plan for the invasion and negotiate with Chiang. According to Liu's 1990 biography, he had asked for a fully-equipped division of 10,000 troops, cavalry, and engineers; another division to maintain order, winter equipment, around 10,000 yaks, additional food supplies, and a truck route from Sichuan to Xikang. Liu also requested that he take sole command of these reinforcements. Later archival documents would confirm Liu's suspicions that the campaign was a plot; once Liu had mobilized his forces, Chiang was to send 30,000 men under his personal command into Xikang and depose Liu. Due to Liu's stalling tactics as well as Allied pressure, the campaign did not materialize.
== Career == Armstrong began his academic career at Rosalind Franklin University of Medicine and Science, where he served as Professor of Surgery and Associate Dean at the Scholl College of Podiatric Medicine. He later moved to Tucson and accepted an offer at the University of Arizona. In 2017, Armstrong was honored as University Distinguished Outreach Professor of Surgery—the first ever in the history of the University of Arizona's Department of Surgery. Following the University of Arizona, Armstrong accepted a position at the Keck School of Medicine of the University of Southern California's Department of Surgery, where he was later named Distinguished Professor of Surgery and Neurological Surgery. In 2025, USC bestowed upon Armstrong the title of Distinguished Professor—one of the university's highest academic honors—making him the first Doctor of Podiatric Medicine to receive this distinction at USC.
Placing a wedge in the felling cut can prevent a sitback from pinching the saw. Freeing: Working a badly fallen tree that may have become trapped in other trees. Working out maximum tension locations to decide the safest way to release tension, and a winch may be needed in complicated situations. To avoid cutting straight through a tree in tension, one or two cuts at the tension point of sufficient depth to reduce tension may be necessary. After tension releases, cuts are made outside the bend. Limbing: Cutting the branches off the log. The operator must be able to properly reach the cut to avoid kickback. Bucking: Cross-cutting the felled log into sections. Setup is made to avoid binding the chainsaw within the changing log tensions and compressions. Safe bucking is started at the log high-side and then sections worked offside, toward the butt end. The offside log falls and allows for gravity to help prevent binds. The log's kerf movement while cutting can help to indicate binds. Additional equipment (lifts, bars, wedges, and winches) and special cutting techniques can help prevent binds. Binds: This is when the chainsaw is at risk or is stuck in the log compression. A log bound chainsaw is unsafe and must be carefully removed to prevent equipment damage. Top bind – The tension area on log bottom, compression on top. Bottom bind – The tension area on log top, compression on bottom. Side bind – Sideways pressure exerted on the log. End bind – Weight compresses the log's entire cross-section.
== Replication == Replication of the R1 plasmid begins at the oriRI site on the plasmid. RepA is the plasma-encoded initiator protein that binds to oriRI in order to initiate replication. RepA needs a 188-bp region of DNA at minimum in order to bind. Initiation of the leading strand, primed by DnaG, occurs at a G-type priming signal. This signal is located 400 bp downstream of the RepA-binding sequences. A newly synthesized RepA protein is used by an oriR on the same template that it was synthesized on, a cis-specific action.
Sources: en.wikipedia.org
If growth is detected, a microbiologist will perform a Gram stain on a sample of blood from the bottle for a rapid preliminary identification of the organism. The Gram stain classifies bacteria as Gram-positive or Gram-negative and provides information about their shape—whether they are rod-shaped (referred to as bacilli), spherical (referred to as cocci), or spiral-shaped (spirochetes)—as well as their arrangement. Gram-positive cocci in clusters, for example, are typical of Staphylococcus species. Yeast and other fungi may also be identified from the Gram stain. A Gram stain identifying microbial growth from a blood culture is considered a critical result and must immediately be reported to the clinician. The Gram stain provides information about the possible identity of the organism, which assists the clinician in the selection of a more appropriate antimicrobial treatment before the full culture and sensitivity results are complete. In traditional methods, the blood is then subcultured onto agar plates to isolate the organism for further testing. The Gram stain results inform microbiologists about what types of agar plates should be used and what tests might be appropriate to identify the organism. In some cases, no organisms are seen on the Gram stain despite the culture bottle showing indicators of growth or being reported as positive by automated instruments. This may represent a false positive result, but it is possible that organisms are present but cannot easily be visualized microscopically.
Robert 'Bob' Ramage FRS (4 October 1935 — 16 October 2019) was an organic chemist, born in Glasgow, who specialised in the synthesis and biosynthesis of natural products, peptides, and proteins. Following his undergraduate degree in chemistry and the University of Glasgow, he stayed on for a PhD in organic chemistry. After his time at Glasgow, he followed his interest in natural products synthesis to Harvard and then Basel, before taking up a lectureship in organic chemistry at the University of Liverpool where his attention was drawn to peptides. His peptide synthesis research continued at the University of Manchester Institute of Science and Technology (UMIST), where he also served as head of department. He returned to Scotland in 1984, taking up the Forbes chair of organic chemistry at the University of Edinburgh, where he remained until retirement in 2000. Outside of academia, in 1994 he founded the company Albachem, which utilised his work with peptides. He was elected Fellow of the Royal Society of Chemistry (1977), Royal Society of Edinburgh (1986), and the Royal Society (1992).
=== Role in cancer progression and therapy resistance === ITGA1 contributes to tumor progression by regulating survival, migration, invasion, and resistance to anticancer therapies. In Pancreatic Ductal Adenocarcinoma (PDAC), ITGA1-mediated collagen EMT signaling promotes the survival of mesenchymal tumor cell populations, metastatic dissemination, and resistance to gemcitabine treatment. Inhibition of ITGA1 increases sensitivity to chemotherapy, making treatment more effective and supporting its capacity as a potential therapeutic target. In glioma, ITGA1 contributes to temozolomide (TMZ) resistance by activating the PI3K/AKT/Bcl-2 signaling pathway. Increased ITGA1 activity promotes anti-apoptotic signaling which prevents tumor cells from apoptosizing therefore leading to survival of tumor cells. Suppressing ITGA1 increases apoptosis and improves TMZ sensitivity. ITGA1 expression in glioma is regulated by the hsa-miR01298-5p pathway, which directly binds the ITGA1 3' untranslated region to suppress ITGA1 expression. Increased ITGA1 reverses those effects, making resistance to chemotherapy more likely.
The physiochemical properties of Benzodiazepines, especially lipophillicity, has a stong influence on the adsorption, metabolism and diffusion. Lipophillic benzodiazepines quickly redistribute to adipose tissue, lowering the concentration in the brain. The main biotransformations of benzodiazepines involve hepatic oxidation, N-dealkylation, hydroxylation and glucuronide conjugation.CYP3A4, CYP3A5 and CYP2C19 are primary enzymes in benzodiazepine metabolism. Glucuronidation is mediated by glucuronyltransferase (UGT). A benzodiazepine can be placed into one of three groups by its elimination half-life, or the time it takes for the body to eliminate half of the dose. Some benzodiazepines have long-acting active metabolites, such as diazepam and chlordiazepoxide, which are metabolised into desmethyldiazepam. Desmethyldiazepam has a half-life of 36–200 hours, and flurazepam, with the main active metabolite of desalkylflurazepam, with a half-life of 40–250 hours. These long-acting metabolites are partial agonists.
The term "MPR vaccine" is also used to refer to this vaccine, whereas "P" refers to parotitis which is caused by mumps. Merck MMR II is supplied freeze-dried (lyophilized) and contains live viruses. Before injection, it is reconstituted with the solvent provided. According to a review published in 2018, the GlaxoSmithKline (GSK) MMR vaccine known as Pluserix "contains the Schwarz measles virus, the Jeryl Lynn–like mumps strain, and RA27/3 rubella virus". Pluserix was introduced in Hungary in 1999. Enders' Edmonston strain has been used since 1999 in Hungary in Merck MMR II product. GSK Priorix vaccine, which uses attenuated Schwarz Measles, was introduced in Hungary in 2003.
Sources: en.wikipedia.org
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
Vladimir Khavinson and colleagues at research institutes in Saint Petersburg developed and studied the peptide. Their program examined short peptides as regulators of aging and neuroendocrine function. Epitalon was one of several compounds produced by that group.